A disgruntled Russian post office worker will not be winning employee of the month after she pepper sprayed a group of customers at the end of a long day.

Video footage of the aftermath shows members of the public – and fellow employees – coughing and wheezing as they try to escape the noxious fumes let off by the short-tempered woman.

Among the victims was an 81-year-old woman who, reports suggest, tried to publicly shame the attacker when she refused to serve her.

The incident took place on 8 November in Nizhny Novgorod, a city in central Russia with more than one million residents.

There were five customers waiting to be served in the post office when the employee informed them they would have to wait until tomorrow because there were only 15 minutes left in the working day.

She ordered them to leave the office and even called them "cockroaches", according to Crime Russia.

That is when the 81-year-old woman stepped in and demanded to be served, declaring the employee a disgrace to the profession of postal workers.

The employee got angry and whipped out her pepper spray canister – aiming it straight into the pensioner's face, before fleeing to the back office.

Within seconds, everyone in the room was experiencing a burning sensation in their eyes, runny noses and whooping coughs. One by one, they fled the building.

The 81-year-old was reported to be worst affected. She, along with the other victims, have demanded that the attacker is sacked by the Russian post office. Police are believed to be taking action.

Customers evacuated the building after the pepper spray was releasedYoutube

According to Medical News Today: Pepper spray is a lachrymatory agent. This means that it makes the eyes tearful. Pepper spray is based on an oil known as oleoresin capsicum. Capsaicin, the inflammatory agent in the oil, is the same chemical that makes chilli peppers hot. But in pepper spray, it is present at a much higher concentration.